.. include:: /Includes.rst.txt
.. _faq:

===
FAQ
===

Why is the editing interface for Content Blocks defined in YAML? Why not just use TCA?
======================================================================================

There are several reasons:

*  Separation of a field's view related properties from it's database related properties
*  Simplification of the definition
*  Prevention of a possible security flaw
*  Opening up to TYPO3 newcomers/ beginners/ frontend-only devs

See :ref:`yaml_reference`.

.. attention::
   Currently there is a long term goal to refactor TCA, but it is unknown when
   this will happen. With Symfony based field types we would not have a breaking
   change in the configuration, but only “under the hood” then.


Switching the CType
===================

Switching the CType without having to re-enter the content is not possible with
different prefixes per CType. If you don't reuse any columns, your data will not
be accessible after switching the CType. (If you switch back, the data is still
there.)

So if you reuse existing fields, CType switching
is possible without data loss between CTypes with the same columns. This is how
the TYPO3 core works and is not specific to content blocks.

Also have alook at the `discussion here <https://decisions.typo3.org/t/
switchable-ctypes-how-to-solve-consistency-issues/660/2>`__ .


Compatibility with extensions
=============================

Introducing the content blocks package approach will be a breaking change. We
offer working together with the extension authors.

Localization of content
=======================

A field is localize-able by default, so setting the localization property is
only necessary if special localization method is required.

Can I reuse an existing field / column?
=======================

Yes you can. You can use the useExistingField property.

For example if you want to use the existing column "bodytext", or "header_layout" or "image" you can do one of the following:

.. code-block:: yaml

    group: common
    fields:
        -
            identifier: header_layout
            type: Select
            properties:
                useExistingField: true
        -
            identifier: bodytext
            type: Textarea
            properties:
                enableRichtext: true
                useExistingField: true
        -
            identifier: image
            type: Image
            properties:
                useExistingField: true